SAN FRANCISCO — A "striking lack of recollection" by White House and military officials prevented congressional investigators from determining who was responsible for misinformation spread after the friendly fire death of Army Ranger Pat Tillman, a House committee said Monday.

Although military investigators determined within days that the onetime NFL player was killed by his own troops in Afghanistan following an enemy ambush, five weeks passed before the circumstances of his death were made public. During that time, the Army claimed Tillman was killed by enemy fire.

Rep. Henry Waxman, chairman of the House Committee on Oversight and Government Reform, said in April 2007 that his goal was to discern the genesis of the misinformation. "Was it the result of incompetence, miscommunication or a deliberate strategy?" he said.

The panel acknowledged Monday it had fallen short of this goal. The committee received a flurry of White House e-mails sent as the Bush administration responded to Tillman's death, but no documents about friendly fire. The committee interviewed several top White House officials about the case, but "not a single one could recall when he learned about the fratricide or what he did in response," it said in its 48-page report.

The committee reported a similar lack of information relating to misinformation surrounding Pvt. Jessica Lynch, who was rescued from an Iraqi hospital after she was badly injured and captured in a 2003 ambush. The committee examined how the story of the ambush of her convoy was changed into a tale of heroism on her part.

"As the committee investigated the Tillman and Lynch cases, it encountered a striking lack of recollection," the report said.

The panel concluded that the lack of information "makes it impossible for the committee to assign responsibility for the misinformation in Corporal Tillman's and Private Lynch's cases."

Jim Wilkinson, a onetime White House official who was communications director for U.S. Central Command, told the committee he did not know where the false information on Lynch originated, or who disseminated it.

In the case of Tillman's April 22, 2004, death, White House officials generated nearly 200 e-mails on the matter the day after, the committee found. Politics seemed to fuel the administration's interest: Several of the e-mails came from the staff of President Bush's re-election campaign, urging Bush to respond publicly.

The White House "rushed" to release a public statement of condolence at about noon on April 23.

But in doing so, the White House violated a military policy enacted into law by Bush himself in 2003, the committee found. The Military Family Peace of Mind Act bars the announcement of a casualty until 24 hours after a family is notified.

The Defense Department, adhering to the policy, had not yet publicly confirmed Tillman's death when the White House released Bush's statement of condolence.

Realizing this belatedly, White House spokewoman Claire Buchan warned her colleagues in an e-mail: "alert _ do not use Tillman statement." But news services were already running the White House statement.

The White House also failed to determine whether information about Tillman's death was classified, the committee found. Tillman's Ranger unit was routinely involved in sensitive operations along the Afghanistan-Pakistan border.

Then-White House communications director Dan Bartlett told the committee he had approved release of the president's statement because of intense news media interest.

The committee cited one exchange between White House political chief Karl Rove and Ron Fournier, then a political reporter for The Associated Press.

In a chain under the subject line "H-E-R-O," Rove replied to an e-mail from Fournier by saying, "How does our country continue to produce men and women like this?"

Fournier replied, "The Lord creates men and women like this all over the world. But only the great and free countries allow them to flourish. Keep up the fight."

Fournier, now the AP's acting Washington bureau chief, said Monday: "I was an AP political reporter at the time of the 2004 e-mail exchange, and was interacting with a source, a top aide to the president, in the course of following an important and compelling story. I regret the breezy nature of the correspondence."

The story of Tillman, a man who gave up a lucrative career in professional sports to serve in the Army, "made the American people feel good about our country ... and our military," Bartlett told the committee. But he acknowledged the statement might "set a precedent."

Another frenzy of White House activity took place, well out of public view, in the days leading up to a Bush speech on Tillman to the annual White House Correspondents' Association dinner, the committee found.

While Bush and other presidents have often delivered humorous remarks to the gathering, Bush had "got singed pretty bad" the previous year for making what some critics perceived as inappropriate joking remarks during wartime, Bartlett said. So the White House made a deliberate decision to "pay tribute to the troops," and made Tillman's death the week before the centerpiece, he said.

Speechwriters and fact-checkers expended hundreds of words in e-mail memos trying to confirm that Tillman and his brother Kevin had joined the Army because of the attacks of Sept. 11, but could not do so, because the brothers had rarely or never spoken publicly about it.

Nevertheless, Bush's remarks to the correspondents' association contained what one White House official admitted was a "speculative" statement by Bush: "Friends say that this young man saw the images of September the 11th, and seeing that evil, he felt called to defend America."

White House spokesman Trey Bohn said Monday that officials there cooperated extensively with the committee during its investigation.

"The report contains no evidence that the White House said anything incorrect or misleading regarding the death of Corporal Tillman," Bohn said. "Our thoughts and prayers remain with the Tillman family."

The authors of the new report carefully avoided assigning blame or intent in either the Tillman or Lynch cases. But, they concluded: "In both cases, affirmative acts created new facts that were significantly different than what the soldiers in the field knew to be true. And in both cases, the fictional accounts proved to be compelling public narratives at difficult times in the war."

The committee also looked into the case of Army Spc. Jesse Buryj of Canton, Ohio. It took nine months for his family to learn that his death in Iraq in May 2004 was not the result of an accidental vehicle crash as they were first told. He was killed by fire from U.S. or Polish soldiers in Karbala after a dump truck hurtled through a checkpoint and crashed into the armored vehicle in which he was riding.

Buryj's parents accepted an invitation to meet Bush at a July 2004 campaign rally. They told investigators they had pressed Bush to help them find answers about their son's death, and said Bush agreed to help.

"A few months later, a Bush-Cheney campaign official contacted the family," the congressional investigators found. "Rather than offer assistance, the official asked Specialist Buryj's mother to appear in a campaign commercial for the president. Mrs. Buryj refused."